Both Lancashire County Council, which operates the contract, and Avacoach, which employed Smith among its 20 drivers, says they were not alerted about Smith’s arrest in summer 2015.

The first Avacoach’s general manager Jeff Dearden knew about it was when Smith failed to turn up at work on April 11 – the day of his sentence.

Today he said: “We are sickened by his behaviour and did not know anything about it.

“He did not turn up for his shift and we could not make contact with him, then we read what had happened in the Evening Post. The police or authorities have not contacted us. It’s a disgrace.”

Smith, 28, of Northgate, Leyland, was jailed for eight months after being found with a stash of thousands of sickening indecent images and videos of youngsters. He admitted three counts of making indecent images of children and one of possessing them.

Police executed a search warrant at his home on Northgate in Leyland at 7.45am on June 2. But due to a failure to alert his employers, Smith was able to work on school runs up until December last year.

A police spokesman said: “The safeguarding of children and young people is the highest priority of Lancashire Police and over the last 12 months we have investigated more than 350 cases of those suspected of being involved in the online abuse of children – making us one of the most proactive forces in the country in this area. It is only thanks to this proactive work that Kieron Smith is now serving a term of imprisonment.

“Following his arrest we imposed strict bail conditions on Smith not to have any unsupervised contact with anyone under 16, but we recognise that in this particular case we could have done more to contact the appropriate authorities, including his employer, given the nature of his work and we will ensure that any lessons are learned so that in future we can live up to our own very high standards.”